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INCOME TAXES - Narratives (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2023 | Sep. 30, 2022
Income Tax Contingency [Line Items] |  |  |  |
Statutory tax rate |  | 21.00% | 21.00% | 21.00%
Net operating loss carryforward |  | $ 52.0 | $ 66.0 |
US and non-US Tax Credit Carryforward |  | $ 10.0 |  |
US and non-US tax credit carryforward expiration period |  | 2025 |  |
Effect of unrecognized tax benefits on effective tax rate |  | $ 14.0 | 17.0 |
Accrual for income tax penalties and interest |  | 4.0 | 6.0 |
Deferred Federal Income Tax Expense (Benefit) |  | (6.0) | $ 28.0 | $ (17.0)
Undistributed Earnings of Foreign Subsidiaries |  | 40.0 |  |
Forecast |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
Unrecognized Tax Benefits, Expected Reduction | $ 2.0 |  |  |
State |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
Net operating loss carryforward |  | $ 816.0 |  |
Minimum |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
Operating Loss Carryforwards, Expiration Year |  | 2025 |  |
Maximum |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
Operating Loss Carryforwards, Expiration Year |  | 2044 |  |
UNITED KINGDOM | Foreign Country Jurisdiction |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
Net operating loss carryforward |  | $ 65.0 |  |
GERMANY | Foreign Country Jurisdiction |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
Net operating loss carryforward |  | $ 54.0 |  |

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